reCAPTCHA issues when using CEF

Having problems with building or using CEF's C/C++ APIs? This forum is here to help. Please do not post bug reports or feature requests here.

reCAPTCHA issues when using CEF

Postby charles » Mon May 11, 2020 6:13 am

Hello,

I am automating certain administrative tasks using CEF without displaying a GUI. Two websites that I'm integrating with are using reCAPTCHAs on their login forms to block (I assume bots for password hacking?) to log in to their service.

When loading these from my normal browser, even in incognito mode, I don't get prompted to enter a captcha. When I load the websites through CEF, it shows me blank reCAPTCHA view that states "Please upgrade to a supported browser to get a reCAPTCHA challenge".

Is there a solution to this? Or is this just a limitation of Google limiting CEF access to certain services, which includes their reCAPTCHA service?

Thanks for all feedback.
charles
Techie
 
Posts: 15
Joined: Wed Apr 01, 2015 6:59 am

Re: reCAPTCHA issues when using CEF

Postby charles » Mon May 11, 2020 10:11 am

Just updated to CEF + Chromium 81 and the issue still persists
charles
Techie
 
Posts: 15
Joined: Wed Apr 01, 2015 6:59 am

Re: reCAPTCHA issues when using CEF

Postby naoki5 » Mon May 11, 2020 8:54 pm

reCAPTCHA will not work if user agent has changed.
Because of that reCAPTCHA didn't work in my application.
There seem to be some other conditions.
naoki5
Techie
 
Posts: 46
Joined: Wed Jul 17, 2019 2:44 am

Re: reCAPTCHA issues when using CEF

Postby amaitland » Tue May 12, 2020 12:17 am

You can load https://recaptcha-demo.appspot.com/reca ... scores.php in different browsers to see what score they've given.
Maintainer of the CefSharp project.
amaitland
Master
 
Posts: 922
Joined: Wed Jan 14, 2015 2:35 am

Re: reCAPTCHA issues when using CEF

Postby magreenblatt » Tue May 12, 2020 11:14 am

amaitland wrote:You can load https://recaptcha-demo.appspot.com/reca ... scores.php in different browsers to see what score they've given.

Interesting link. I'm getting the same results with cefclient 80.1.15+g7b802c9+chromium-80.0.3987.163, cefclient 81.3.5+gb547de9+chromium-81.0.4044.138 and Google Chrome 81.0.4044.138 (Official Build) (64-bit) on Windows 10. I wonder what would cause a worse result (maybe a really old Chromium version, or some networks-specific conditional like IP address range?).

{
"success": true,
"hostname": "recaptcha-demo.appspot.com",
"challenge_ts": "2020-05-12T16:07:42Z",
"apk_package_name": null,
"score": 0.9,
"action": "examples/v3scores",
"error-codes": []
}
magreenblatt
Site Admin
 
Posts: 10853
Joined: Fri May 29, 2009 6:57 pm

Re: reCAPTCHA issues when using CEF

Postby magreenblatt » Tue May 12, 2020 11:17 am

I get a different (worse?) score in the current version of Firefox (76.0.1 (64-bit)).

{
"success": true,
"hostname": "recaptcha-demo.appspot.com",
"challenge_ts": "2020-05-12T16:16:13Z",
"apk_package_name": null,
"score": 0.7,
"action": "examples/v3scores",
"error-codes": []
}
magreenblatt
Site Admin
 
Posts: 10853
Joined: Fri May 29, 2009 6:57 pm

Re: reCAPTCHA issues when using CEF

Postby Czarek » Tue May 12, 2020 1:09 pm

reCaptcha score depends on IP address, browser cookies and possibly other things. It can quickly change if you make too many queries from that ip address and restarts back to good score after some time.
Maintainer of the CEF Python, PHP Desktop and CEF C API projects. Connect with me on LinkedIn.
User avatar
Czarek
Virtuoso
 
Posts: 1905
Joined: Sun Nov 06, 2011 2:12 am

Re: reCAPTCHA issues when using CEF

Postby amaitland » Tue May 12, 2020 2:26 pm

A few years ago CefSharp was scoring a 0.1 which made it totally impossible to solve, cefclient in comparison was scoring a 0.7 which was harder to solve than chrome, still usable. Turns out they were fingerprinting CefSharp specifically based on a v8 extension(CefRegisterExtension).

From memory CEF's score improved when mp3 patent expired and default builds include support (the accessible recaptch was an mp3 audio file).

I'd be testing with cefclient on the OPs machine to see what score they're given.
Maintainer of the CefSharp project.
amaitland
Master
 
Posts: 922
Joined: Wed Jan 14, 2015 2:35 am

Re: reCAPTCHA issues when using CEF

Postby charles » Wed May 13, 2020 3:54 pm

Update: Google states reCaptcha is only supported on the last 2 browser versions of Chrome. Since updating to Chromium 81 (using the latest Spotify build) I'm now getting 0.9 as my CEF score. This is with the default Chrome user agent string. Before I was using 79 and that wouldn't even load the captcha.
charles
Techie
 
Posts: 15
Joined: Wed Apr 01, 2015 6:59 am


Return to Support Forum

Who is online

Users browsing this forum: No registered users and 15 guests